Manufacturing electronic circuits on rigid PCB's (printed circuit boards) constructed of, for example, epoxy glass laminate is well known. For consumer products such as pagers, watches and hand-held calculators, rigid PCB's have provided an effective method for the manufacture of such products.
However, as miniaturization continues to be a driving force in the technology market, new methods are under investigation to determine how to reduce the thickness of PCB's and more importantly how to manufacture new PCB technologies reliably and at low cost. As a byproduct of these investigations, engineers have turned their interest to the use of flexible substrates for carrying a multiplicity of circuits that traditionally were carried by rigid PCB's. Such substrates are constructed of, for example, polyimide material and are readily available at a low cost.
Although flexible PCB substrates have the attractive feature of being inexpensive, their lack of rigidity has made manufacturability a complex challenge. Presently, the manufacture of dense circuits, which include fine-pitch surface mount devices, is expensive and not easily repeatable in a reliable fashion over large volumes of flexible PCB substrates. Yet another disadvantage in prior art manufacturing machines is their inability to salvage portions of a substrate when one of the manufacturing machines experiences a fault causing the manufacturing line to cease operation.
Accordingly, a method and apparatus would be desirable that would overcome the foregoing disadvantages described in the prior art.